Republicans have to be continually humiliated in front of the nation. That is the only thing that will work, and that is all that they will listen to (other than outright brutality). Utter and complete humiliation every day.
Dems as a party won’t do it because they a) fear losing imaginary “centrist” voters, and b) don’t actually want to be in power anyway, since they can fundraise more when they are in the opposition.